1. Field of the Invention
The instant invention relates generally to threaded fasteners and more specifically it relates to an improved relief screw.
2. Description of the Prior Art
Numerous threaded fasteners have been provided in prior art that are adapted to attach various articles together. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.
For example, U.S. Pat. No. 2,199,809 to Pigott teaches a bolt with a multi-layered head of decreasing diameter. Its threads do not continue all the way to the head. Thread threads on the shaft are for a nut, so that access behind the wall is a necessity.
U.S. Pat. No. 3,056,234 to Nelsson et al. teaches a screw with a head that is frustum shaped having a non-rectilinear slat height (curved not straight). There is no flange present on its head.
U.S. Pat. No. 3,177,755 to Kahn teaches a screw with a multi-layered head of decreasing diameter. Its threads do not continue all the way to its head. Its head is frustum shaped with a non-rectilinear slant height (curved not straight). There is no flange present on its head and its head is textured.
U.S. Pat. No. 3,903,784 to Dekker teaches a screw with a head that is frustum shaped and contains a plurality of cutters around its slant height. Its threads do not continue all the way from its tip to its head.
U.S. Pat. No. 4,653,244 to Farrell teaches a screw with a head that is frustum shaped with a non-rectilinear slant height (curved not straight). There are both right handed and left handed threads on its shaft. Its head flange is textured and there is a second frustum on its shaft mating with its head.